Revolut test

Design and implement a RESTful API (including data model and the backing implementation) for money transfers between accounts.

Explicit requirements:

1. You can use Java, Scala or Kotlin.
2. Keep it simple and to the point (e.g. no need to implement any authentication).
3. Assume the API is invoked by multiple systems and services on behalf of end users.
4. You can use frameworks/libraries if you like (except Spring), but don't forget about
   requirement #2 – keep it simple and avoid heavy frameworks.
5. The datastore should run in-memory for the sake of this test.
6. The final result should be executable as a standalone program (should not require
   a pre-installed container/server).
7. Demonstrate with tests that the API works as expected.

Implicit requirements:

9. The code produced by you is expected to be of high quality.
10. There are no detailed requirements, use common sense.

Information

Libraries

Web container to serve the app

• Jetty

REST API (JAX-RS)

• Jersey

In-memory database

• H2

Database migration

• Flyway

Load application properties file

• Commons Configuration2
• Commons BeanUtils

Unit test

• JUnit 5
• Mockito

Hosted continuous integration service

• Travis CI

Hosted code coverage

• Coveralls

Local code coverage

• JaCoCo

RestFul integration test

• REST Assured

JDBC Connection Pool (Allow get async connections)

• Tomcat JDBC

Instructions

Test

$ gradlew test

Build

$ gradlew build

Run

$ java -jar revolut-1.0-SNAPSHOT-all.jar

Server

The Application starts a jetty server on localhost port 8080 with two sample accounts

• http://localhost:8080/api/account/18181818

Response:

{
    "id": 18181818,
    "name": "Jullierme Barros",
    "balance": 1000000.00
} 

• http://localhost:8080/api/account/17171717

Response:

{
    "id": 17171717,
    "name": "Manoela Barros",
    "balance": 1000000.00
} 

Available Services

HTTP METHOD	PATH	USAGE
POST	/api/account	create a new account
GET	/api/account/{accountId}	get account by accountId
POST	/api/transaction	perform transaction between 2 accounts
GET	/api/transaction/{transactionId}	get transaction by id

Http Status

• 200 OK
• 400 Bad Request
• 404 Not Found
• 500 Internal Server Error

Sample JSON for Account and Transaction

Account:

Request:

{  
   "name":"Jullierme",
   "balance":100
} 

Response:

Header:
"Location":"http://localhost:8080/api/account/18181819"

Transaction:

Request:

{  
   "fromAccountId":18181818,
   "toAccountId":17171717
   "amount":10,
}

Response:

{
    "id": 1,
    "fromAccountId": 18181818,
    "toAccountId": 17171717,
    "amount": 10.00
}

More information

• To ensure that an account does not transfer amounts without balance, the transfer method uses database transaction control.
• To check asynchronous tests, please see the classes * StressTest.java